<?php /** * TSqlMapPagedList class file. * * @author Wei Zhuo <weizhuo[at]gmail[dot]com> * @link http://www.pradosoft.com/ * @copyright Copyright © 2005-2008 PradoSoft * @license http://www.pradosoft.com/license/ * @version $Id$ * @package System.Data.SqlMap */ Prado::using('System.Collections.TPagedList'); /** * TSqlMapPagedList implements a list with paging functionality that retrieves * data from a SqlMap statement. * * The maximum number of records fetched is 3 times the page size. It fetches * the current, the previous and the next page at a time. This allows the paged * list to determine if the page is a the begin, the middle or the end of the list. * * The paged list does not need to know about the total number of records. * * @author Wei Zhuo <weizhuo[at]gmail[dot]com> * @version $Id$ * @package System.Data.SqlMap * @since 3.1 */ class TSqlMapPagedList extends TPagedList { private $_statement; private $_parameter; private $_prevPageList; private $_nextPageList; private $_delegate=null; /** * Create a new SqlMap paged list. * @param IMappedStatement SqlMap statement. * @param mixed query parameters * @param int page size * @param mixed delegate for each data row retrieved. * @param int number of page to fetch on initialization */ public function __construct(IMappedStatement $statement,$parameter, $pageSize, $delegate=null, $page=0) { parent::__construct(); parent::setCustomPaging(true); $this->initialize($statement,$parameter, $pageSize, $page); $this->_delegate=$delegate; } /** * Initialize the paged list. * @param IMappedStatement SqlMap statement. * @param mixed query parameters * @param int page size. * @param int number of page. */ protected function initialize($statement, $parameter, $pageSize, $page) { $this->_statement = $statement; $this->_parameter = $parameter; $this->setPageSize($pageSize); $this->attachEventHandler('OnFetchData', array($this, 'fetchDataFromStatement')); $this->gotoPage($page); } /** * @throws TSqlMapException custom paging must be enabled. */ public function setCustomPaging($value) { throw new TSqlMapException('sqlmap_must_enable_custom_paging'); } /** * Fetch data by executing the SqlMap statement. * @param TPageList current object. * @param TPagedListFetchDataEventParameter fetch parameters */ protected function fetchDataFromStatement($sender, $param) { $limit = $this->getOffsetAndLimit($param); $connection = $this->_statement->getManager()->getDbConnection(); $data = $this->_statement->executeQueryForList($connection, $this->_parameter, null, $limit[0], $limit[1], $this->_delegate); $this->populateData($param, $data); } /** * Switches to the next page. * @return integer|boolean the new page index, false if next page is not availabe. */ public function nextPage() { return $this->getIsNextPageAvailable() ? parent::nextPage() : false; } /** * Switches to the previous page. * @return integer|boolean the new page index, false if previous page is not availabe. */ public function previousPage() { return $this->getIsPreviousPageAvailable() ? parent::previousPage() : false; } /** * Populate the list with the fetched data. * @param TPagedListFetchDataEventParameter fetch parameters * @param array fetched data. */ protected function populateData($param, $data) { $total = $data instanceof TList ? $data->getCount() : count($data); $pageSize = $this->getPageSize(); if($total < 1) { $param->setData($data); $this->_prevPageList = null; $this->_nextPageList = null; return; } if($param->getNewPageIndex() < 1) { $this->_prevPageList = null; if($total <= $pageSize) { $param->setData($data); $this->_nextPageList = null; } else { $param->setData(array_slice($data, 0, $pageSize)); $this->_nextPageList = array_slice($data, $pageSize-1,$total); } } else { if($total <= $pageSize) { $this->_prevPageList = array_slice($data, 0, $total); $param->setData(array()); $this->_nextPageList = null; } else if($total <= $pageSize*2) { $this->_prevPageList = array_slice($data, 0, $pageSize); $param->setData(array_slice($data, $pageSize, $total)); $this->_nextPageList = null; } else { $this->_prevPageList = array_slice($data, 0, $pageSize); $param->setData(array_slice($data, $pageSize, $pageSize)); $this->_nextPageList = array_slice($data, $pageSize*2, $total-$pageSize*2); } } } /** * Calculate the data fetch offsets and limits. * @param TPagedListFetchDataEventParameter fetch parameters * @return array 1st element is the offset, 2nd element is the limit. */ protected function getOffsetAndLimit($param) { $index = $param->getNewPageIndex(); $pageSize = $this->getPageSize(); return $index < 1 ? array($index, $pageSize*2) : array(($index-1)*$pageSize, $pageSize*3); } /** * @return boolean true if the next page is available, false otherwise. */ public function getIsNextPageAvailable() { return $this->_nextPageList!==null; } /** * @return boolean true if the previous page is available, false otherwise. */ public function getIsPreviousPageAvailable() { return $this->_prevPageList!==null; } /** * @return boolean true if is the very last page, false otherwise. */ public function getIsLastPage() { return ($this->_nextPageList===null) || $this->_nextPageList->getCount() < 1; } /** * @return boolean true if is not first nor last page, false otherwise. */ public function getIsMiddlePage() { return !($this->getIsFirstPage() || $this->getIsLastPage()); } }